Proposal to observe paths superpositions in a double-slit setup

TL;DR

This paper proposes a method using weak measurements to observe superpositions of paths in a double-slit experiment, aiming to directly visualize quantum trajectories without significantly disturbing the system.

Contribution

It introduces a novel protocol for observing weak trajectories of photons in a double-slit setup, providing a new way to visualize quantum path superpositions.

Findings

Demonstrates the feasibility of observing weak trajectories with minimal disturbance

Proposes a simplified protocol for single-photon experiments

Provides theoretical foundation for direct visualization of quantum paths

Abstract

The interference pattern produced by a quantum particle in Young's double-slit setup is attributed to the particle's wavefunction having gone through both slits. In the path integral formulation, this interference involves a superposition of paths, going through either slit, linking the source to the detection point. We show how these paths superpositions can in principle be observed by implementing a series of minimally-perturbing weak measurements between the slits and the detection plane. We further propose a simplified protocol in order to observe these "weak trajectories" with single photons.